The federal government is struggling to conduct background checks on people seeking security clearances, creating a backlog that one industry group says encompasses more than 700,000 applicants.

As of March, the process for a top secret security clearance took more than 450 days to conclude, a federal official reported in May, more than a half-year longer than it took in April 2016.

As the backlog has mounted, the Office of Personnel Management recently stopped reporting on the numbers of people waiting for approval. The decision to halt reporting comes as George Nesterczuk, the man President Trump nominated to lead the effort withdrew his name from consideration, leaving OPM without a permanent director.

The delay is complicating life for government contractors, as a shortage of cleared, qualified employees makes it hard to fill key positions and put people to work on sensitive projects.

“This is a giant, giant problem,” said Andrew Hunter, a military procurement expert with the Center for Strategic and International Studies.

“I’m told there are billions of dollars being spent for people who are on payrolls but they’re not able to do the work because they’re waiting for a clearance,” he added.

Processing clearance requests has long been an issue in Washington but the process slowed considerably after 2013, when former National Security Agency contractor Edward Snowden leaked classified information to news organizations even though he had been cleared.

That same year a shooting by a cleared government employee in the District’s Navy Yard neighborhood again raised concerns the government was approving too many people, prompting the government to overhaul the screening process.

The government’s problems were compounded in 2015 when clearance investigations were temporarily suspended after hackers breached OPM’s computer systems and made employees’ confidential personal information available online, revealing new flaws in the system.

“This really all started with the OPM breach,” said Bill Greenwalt, a defense consultant who was the Defense Department’s deputy undersecretary for defense industrial policy in the George W. Bush administration. “I think it’s gotten so bad that they stopped publishing it … there’s no sign of this backlog doing anything but growing.”

A spokesman from the Defense Security Service, which handles clearance issues at the Defense Department, said the agency forwarded questions to OPM. Officials at OPM did not respond to questions related to size of the backlog.

Last year, the agency reported the backlog of unfinished clearances was roughly 570,000. More recently, Clearancejobs.com, a trade publication, reported last month the backlog had grown to 690,000. The Aerospace Industry Association, which lobbies on behalf of defense manufacturers, said in a Thursday blog post the backlog has grown to more than 700,000, based on information it said it received from unnamed government individuals.

The government’s decision to stop reporting the size of the backlog came as part of a broader effort to streamline agencies’ operations and realign their goals with the new administration.

In a June 15 memo from Office of Management and Budget, the White House discontinued a broad set of reporting standards that existed under the Obama administration. The memo said new administrative goals are being established as part of the president’s next budget.

“Too often, burdensome tasks have piled up without consideration of whether the requirements collectively make sense,” OMB Director Mick Mulvaney said in the memo. “In many cases, agencies are asked to spend more time and resources complying with low-value activities versus allocating taxpayer dollars to meet their core agency mission.”

Industry groups say the directive has made it harder for them to track OPM’s progress.

“In plain English, the OMB memo tells OPM to stop reporting progress toward reducing the security clearance backlog, and to the best of our knowledge, they have stopped,” said David Berteau, president and chief executive of the Professional Services Council, which lobbies on behalf of government contractors.

Members of Congress are pushing the agency for more transparency on the issue. In late July, the House unanimously passed a bill that would require OPM to produce quarterly reports detailing the size of the clearance backlog and the average time it takes to complete an investigation.

In the meantime, government services firms say the shortage of skilled, cleared employees is igniting a war for talent and in some cases disrupting government work.

Defense manufacturer Raytheon recently reported in a white paper that it requested 2,348 clearances at the “secret” level between January 2016 and April 2017 for newly hired employees, and that 72 percent of them had not been filled as of April 2017. The firm reported individual cases typically took close to a year to conclude.

“Many talented employment prospects simply decide to seek alternative employment, rather than wait for a clearance determination,” the Raytheon white paper reads. “These departures not only undermine industry’s ability to recruit the best and brightest for government programs, they also impose additional costs to government programs as new candidates must be identified, hired, and resubmitted for clearances.”

It may also be driving up wages for the limited pool of workers that already have clearances. The Human Resources Association of the National Capital Area, which tracks payroll trends, found in 2013 that having a clearance is associated with five to 15 percent higher wages depending on the clearance level.